Boros István (szerk.): A Magyar Természettudományi Múzeum évkönyve 52. (Budapest 1960)
Móczár, L.: The loess wall of Tihany and the nesting of Odynerus spiricornis Spin. (Hymenoptera, Eumenidae)
ANNALES HISTORICO-NATURALES MUSEI NATIONALIS HUNGARICI Tomus 52. PARS ZOOLOGICA 1960. The Loess Wall of Tihany and the Nesting of Odynerus spiricornis Spin. (Hymenoptera, Eumenidae) By L. MÓCZÁR, Budapest In the center of the almost 6 kms long Tihany Peninsula of the Balaton, there rises a 23 m long and 4 m high wall — some 10 meters above the surface of the Lake, on the western slope of the Csúcshegy along the Southern shore (Plate I, fig. 1). It consists mainly of loess, only its lower (western part) being of sedimentary rocks, in which there are mixed the fragments of the geyser cones frequent in the Peninsula, together with some clay and limestone. Above the loess wall, there rises a slope of grasses (Festucetum sulcatae) and mixed, weedy forests characteristical of the Tihany Peninsula : karstic oak shrubs and calciphilous oakwoods. No vegetation developed on the loess wall itself. One may observe but some sterns of Agropyron intermedium (Mediterranean), Artemisia campestris (Mediterranean-continental-Eiirasian), Centaurea rhenana (Med.-cont.-Central European), and the fruit-bearing stalks of Sisymbrium orientate (Pontic Mediterranean). There are also smaller patches of the typically loess-dwelling mosses, Barbula austriaca and Pterygoneurum pusillum (det. E. V a j d a). At the base of the loess wall, these plants unite into a more or less close cover, with an admixture of the following species : Allium flavum (Mediterranean), Coronilla caria and Xeranthemum annuurn (PonticMediterranean), Artemisia austriaca, Medicago falcata and Reseda lutea (Eurasian), Astragalus austriacus, Linaria genistijolia , Stipa capillata, Thymus sp. (Continental), Convolvulus arvensis (Cosmopolitan). Centaurea micranthos (Pontic). The southern, southeastern, that is, continental character of the vegetation is therefore obvious (det. L. Felföld i). Tall trees shadow the two sides of the wall. About 12 m- of the second quarter of the loess wall (6 m long, 2,80 m high in its western, and 1,30 m high in its eastern side) is sheltered from any wind, since no higher vegetation could grow in front of the steep wall, and so the Sun may heat it freely (Plate I, fig. 2). Due to the favourable situation and the remote location from any r traffic of the loess precipice, a special insect fauna of a southern character, similar to the vegetation, had been able to develop on its surface. I. The insects of the loess wall The insects observed on the loess wall may be relegated into four groups, in accordance with Roller (1936). 1. Xenocoen species, taking their time but transitionally in the biotop. These either live in the surrounding areas and reach the loess wall only during their wanderings, or they look up the wall for the more intensive sunshine, therefore for the sake of receaving heat. Such were Vanessa c-album, Syrphids, the specimens of Auplopus carbonarius Scop., which flew about the wall, searching around in the cracks, or carrying their spider preys upwards on the steep slope. It is worthy to note that the legs of the spiders were not amputated, as is otherwise the custom of these wasps. Cryptochelius affinis Lind., Paracyphononyx luctuosus Mocs., and Anoplius fuscus f. paganus Dhlb. have repeatedly hurried along the base of the loess wall. Halictus specimens hovered near, and the workers of
